evennia/src/commands/cmdparser.py

250 lines
8.5 KiB
Python

"""
The default command parser. Use your own by assigning
settings.ALTERNATE_PARSER to a Python path to a module containing the
replacing cmdparser function. The replacement parser must
return a CommandCandidates object.
"""
def cmdparser(raw_string, cmdset, caller, match_index=None):
"""
This function is called by the cmdhandler once it has
gathered all valid cmdsets for the calling player. raw_string
is the unparsed text entered by the caller.
The cmdparser understand the following command combinations (where
[] marks optional parts.
[cmdname[ cmdname2 cmdname3 ...] [the rest]
A command may consist of any number of space-separated words of any
length, and contain any character.
The parser makes use of the cmdset to find command candidates. The
parser return a list of matches. Each match is a tuple with its
first three elements being the parsed cmdname (lower case),
the remaining arguments, and the matched cmdobject from the cmdset.
"""
def create_match(cmdname, string, cmdobj):
"""
Evaluates the quality of a match by counting how many chars of cmdname
matches string (counting from beginning of string). We also calculate
a ratio from 0-1 describing how much cmdname matches string.
We return a tuple (cmdname, count, ratio, args, cmdobj).
"""
cmdlen, strlen = len(cmdname), len(string)
mratio = 1 - (strlen - cmdlen) / (1.0 * strlen)
args = string[cmdlen:]
return (cmdname, args, cmdobj, cmdlen, mratio)
if not raw_string:
return None
matches = []
# match everything that begins with a matching cmdname.
l_raw_string = raw_string.lower()
for cmd in cmdset:
matches.extend([create_match(cmdname, raw_string, cmd)
for cmdname in [cmd.key] + cmd.aliases
if cmdname and l_raw_string.startswith(cmdname.lower())])
if not matches:
# no matches found.
if '-' in raw_string:
# This could be due to the user trying to identify the
# command with a #num-<command> style syntax.
mindex, new_raw_string = raw_string.split("-", 1)
if mindex.isdigit():
mindex = int(mindex) - 1
# feed result back to parser iteratively
return cmdparser(new_raw_string, cmdset, match_index=mindex)
# only select command matches we are actually allowed to call.
matches = [match for match in matches if match[2].access(caller, 'cmd')]
if len(matches) > 1:
# see if it helps to analyze the match with preserved case.
matches = [match for match in matches if raw_string.startswith(match[0])]
if len(matches) > 1:
# we still have multiple matches. Sort them by count quality.
matches = sorted(matches, key=lambda m: m[3])
# only pick the matches with highest count quality
quality = [mat[3] for mat in matches]
matches = matches[-quality.count(quality[-1]):]
if len(matches) > 1:
# still multiple matches. Fall back to ratio-based quality.
matches = sorted(matches, key=lambda m: m[4])
# only pick the highest rated ratio match
quality = [mat[4] for mat in matches]
matches = matches[-quality.count(quality[-1]):]
if len(matches) > 1 and match_index != None and 0 <= match_index < len(matches):
# We couldn't separate match by quality, but we have an index argument to
# tell us which match to use.
matches = [matches[match_index]]
# no matter what we have at this point, we have to return it.
return matches
#------------------------------------------------------------
# Search parsers and support methods
#------------------------------------------------------------
#
# Default functions for formatting and processing searches.
#
# This is in its own module due to them being possible to
# replace from the settings file by setting the variables
#
# SEARCH_AT_RESULTERROR_HANDLER
# SEARCH_MULTIMATCH_PARSER
#
# The the replacing modules must have the same inputs and outputs as
# those in this module.
#
def at_search_result(msg_obj, ostring, results, global_search=False):
"""
Called by search methods after a result of any type has been found.
Takes a search result (a list) and
formats eventual errors.
msg_obj - object to receive feedback.
ostring - original search string
results - list of found matches (0, 1 or more)
global_search - if this was a global_search or not
(if it is, there might be an idea of supplying
dbrefs instead of only numbers)
Multiple matches are returned to the searching object
as
1-object
2-object
3-object
etc
"""
string = ""
if not results:
# no results.
string = "Could not find '%s'." % ostring
results = None
elif len(results) > 1:
# we have more than one match. We will display a
# list of the form 1-objname, 2-objname etc.
# check if the msg_object may se dbrefs
show_dbref = global_search
string += "More than one match for '%s'" % ostring
string += " (please narrow target):"
for num, result in enumerate(results):
invtext = ""
dbreftext = ""
if hasattr(result, "location") and result.location == msg_obj:
invtext = " (carried)"
if show_dbref:
dbreftext = "(#%i)" % result.id
string += "\n %i-%s%s%s" % (num+1, result.name,
dbreftext, invtext)
results = None
else:
# we have exactly one match.
results = results[0]
if string:
msg_obj.msg(string.strip())
return results
def at_multimatch_input(ostring):
"""
Parse number-identifiers.
This parser will be called by the engine when a user supplies
a search term. The search term must be analyzed to determine
if the user wants to differentiate between multiple matches
(usually found during a previous search).
This method should separate out any identifiers from the search
string used to differentiate between same-named objects. The
result should be a tuple (index, search_string) where the index
gives which match among multiple matches should be used (1 being
the lowest number, rather than 0 as in Python).
This parser version will identify search strings on the following
forms
2-object
This will be parsed to (2, "object") and, if applicable, will tell
the engine to pick the second from a list of same-named matches of
objects called "object".
Ex for use in a game session:
> look
You see: ball, ball, ball and ball.
> get ball
There where multiple matches for ball:
1-ball
2-ball
3-ball
4-ball
> get 3-ball
You get the ball.
"""
if not isinstance(ostring, basestring):
return (None, ostring)
if not '-' in ostring:
return (None, ostring)
try:
index = ostring.find('-')
number = int(ostring[:index])-1
return (number, ostring[index+1:])
except ValueError:
#not a number; this is not an identifier.
return (None, ostring)
except IndexError:
return (None, ostring)
def at_multimatch_cmd(caller, matches):
"""
Format multiple command matches to a useful error.
"""
string = "There where multiple matches:"
for num, match in enumerate(matches):
# each match is a tuple (candidate, cmd)
cmdname, arg, cmd, dum, dum = match
is_channel = hasattr(cmd, "is_channel") and cmd.is_channel
if is_channel:
is_channel = " (channel)"
else:
is_channel = ""
is_exit = hasattr(cmd, "is_exit") and cmd.is_exit
if is_exit and cmd.destination:
is_exit = " (exit to %s)" % cmd.destination
else:
is_exit = ""
id1 = ""
id2 = ""
if not (is_channel or is_exit) and (hasattr(cmd, 'obj') and cmd.obj != caller):
# the command is defined on some other object
id1 = "%s-" % cmd.obj.key
id2 = " (%s-%s)" % (num + 1, cmdname)
else:
id1 = "%s-" % (num + 1)
id2 = ""
string += "\n %s%s%s%s%s" % (id1, cmdname, id2, is_channel, is_exit)
return string